Citral and eugenol modulate DNA damage and pro-inflammatory mediator genes in murine peritoneal macrophages

Abstract

Citral and eugenol have been broadly studied because of their anti-inflammatory, antioxidant and antiparasitic potentials. In this study, the effects of citral (25, 50 and 100 µg/mL) and eugenol (0.31, 0.62, 1.24 and 2.48 µg/mL) on the expression (RT-PCR) of the pro-inflammatory mediator genes NF-κB1, COX-2 and TNF-α were evaluated in mouse peritoneal macrophages with or without activation by a bacterial lipopolysaccharide (LPS). Additionally, the genotoxic potentials of two compounds and their capacities to modulate the DNA damage induced by doxorubicin (DXR) were investigated using the comet assay. The data revealed that neither citral nor eugenol changed COX-2, NF-κB1 or TNF-α expression in resting macrophages. However, in LPS-activated cells, citral induced the hypoexpression of COX-2 (100 µg/mL) and TNF-α (50 and 100 µg/mL). Hypoexpression of TNF-α was also detected after cellular exposure to eugenol at the highest concentration (2.48 µg/mL). Both compounds exhibited genotoxic potential (citral at 50 and 100 µg/mL and eugenol at all concentrations) but also showed chemopreventive effects, in various treatment protocols. Both citral and eugenol might modulate inflammatory processes and DXR-induced DNA damage, but the use of these compounds must be viewed with caution because they are also able to induce primary DNA lesions.

Anti-Inflammatory Activity of the Essential Oil Citral in Experimental Infection withStaphylococcus aureusin a Model Air Pouch

“…Although few studies can be found in the literature on the influence of monoterpene compounds in modulating gene expression of TNF- α , there are reports that citral oil inhibits an increase in TNF- α levels in RAW 264.7 cells that are stimulated with lipopolysaccharide (LPS) [33]. In the same way, it was observed in the literature that the EOC at concentrations of 50 and 100  μ g/mL reduced the TNF- α relative expression compared to treatment with LPS [34]. Authors analyzing alveolar macrophages observed that treatment with citral oil in mice with lung injury induced by LPS inhibited TNF- α , IL-1 β , and IL-6 levels both in vivo and in vitro, demonstrating that the EOC can inhibit a possible inflammatory response [18].…”

Chemical Composition and Evaluation of Antibacterial Activities of Essential Oil from Lemon (Citrus aurantifolia L.) Leaves Growing Tien Giang Province, Vietnam

“…The major components were α-pinene (27.982 %) and βcitral (20.06%). Previous studies showed that α-citral, β-citral might modulate inflammatory processes and DNA damage [33,34], which is followed by D-limonene, acetic acid, nerol, nerol acetate, citronellol and caryophyllene oxide at 15.73, 6.36, 4.41, 3.49, 2.193 and 2.01 %, respectively. Besides geographical location differences, the season of harvest and plant age, the abundance of citral constituent could be due to the influence of microwave irradiation, which causes oxygen containing polar molecules, such as water and citral molecules, to spin rapidly.…”

Piper betleoides C. DC.: Edible source of betel‐scented sesquiterpene‐rich essential oil

“…Though the carcinogenicity of eugenol was found to be equivocal on B6C3F1 mice as per the National Toxicology Program Technical Report, USA (1983), multiple studies in the last decade have revealed the genotoxicity of eugenol. It has been reported to induce chromosomal aberrations, endoreduplication and primary DNA damage . Therefore, an alternative plant source producing betel‐scented essential oil with low abundance of phenylpropanoids may be useful as a safer alternative to P betle in the flavour industries.…”

“…It has been reported to induce chromosomal aberrations, endoreduplication and primary DNA damage. [17][18][19][20] Therefore, an alternative plant source producing betel-scented essential oil with low abundance of phenylpropanoids may be useful as a safer alternative to P betle in the flavour industries. Recently, a group of researchers from Thailand has reported the essential oil composition from eight different species of Piper possessing betel-like scent.…”